Electrical components, such as inductors, capacitors, computer chips, and the like, are increasingly in demand for a broad range of applications. Along with the increased overall need for these components, there is a drive to make the components more miniaturized in size and footprint. Smaller electrical components carry through to smaller electrical devices, such as telephones and portable music player devices.
Electrical devices known as baluns are typically used to convert unbalanced electrical signals to balanced signals. A balun that operates in a low frequency band and is used to connect a balanced transmission line to an unbalanced line generally consists of a concentrated constant component such as a transformer, whereas a balun that operates in a high-frequency microwave band consists of a distributed constant component. Baluns known in the art consist of a distributed constant component, including a quarter-wavelength matching element, or include transformers having a size determined according to usable wavelengths.
Because baluns incorporating a distributed line topology necessarily include the requirement of the length of the respective “line” to be in the order of one-fourth of the wavelength at the operating frequency, line length requirements limit low frequency applications. Transformer characteristics also limit allowable frequencies. As a result, a major disadvantage to conventional balun designs is that respective frequency bands are fundamentally narrow.
A need exists for a balun device that realizes a compact design yet is usable in a wide band of frequency applications. The design would benefit from compatibility with existing semiconductor technologies that allow for integration of electrical components in semiconductor devices.